linklayerprotocols/tundriver/src/tundriverbinder.cpp
branchRCL_3
changeset 63 425d8f4f7fa5
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/linklayerprotocols/tundriver/src/tundriverbinder.cpp	Wed Sep 15 00:18:51 2010 +0300
@@ -0,0 +1,729 @@
+/**
+*   Copyright (c) 2010 Nokia Corporation and/or its subsidiary(-ies).
+*   All rights reserved.
+*   This component and the accompanying materials are made available
+*   under the terms of "Eclipse Public License v1.0"
+*   which accompanies this distribution, and is available
+*   at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*   
+*   Initial Contributors:
+*   Nokia Corporation - initial contribution.
+*   
+*   Contributors:
+*
+*   Description:
+*   Ipv4 and Ipv6 Binder configuration source file.
+* 
+*
+*/
+
+/**
+ @file tundriverbinder.cpp
+ @internalTechnology
+ */
+
+#include <e32std.h>
+#include <eui_addr.h>
+#include <ip4_hdr.h>
+#include <udp_hdr.h>
+#include <in_chk.h>
+#include <in_iface.h>
+#include <comms-infras/nifif.h>
+#include <in_sock.h>
+#include <flow.h>
+#include "tundriverbinder.h"
+#include "tundriverprovision.h"
+
+using namespace ESock;
+
+#ifdef _DEBUG
+_LIT8(KNif,"TunDriver");
+_LIT8(KBinder4,"Binder4");
+#ifdef IPV6SUPPORT
+_LIT8(KBinder6,"Binder6");
+#endif
+#endif
+
+//////////////////////
+// CTunDriverBinder //
+//////////////////////
+
+CTunDriverBinder::CTunDriverBinder(CTunDriverSubConnectionFlow& aTunDriverSubConnectionFlow) : iTunDriverSubConnectionFlow(aTunDriverSubConnectionFlow)
+/*
+* Default constructor for Binder Base Class.
+*/
+        {
+        }
+
+MLowerDataSender* CTunDriverBinder::Bind(MUpperDataReceiver& /*aUpperReceiver*/, MUpperControl& /*aUpperControl*/)
+/**
+* Virtual Function, Implementation is binder specific (IPv4 or IPv6)
+* If This Bind function is called, then there is an error in binding.
+* @param Not used here
+* @return NULL.
+*/
+    {
+    return NULL;
+    }
+
+void CTunDriverBinder::Unbind(MUpperDataReceiver& /*aUpperReceiver*/, MUpperControl& /*aUpperControl*/)
+/**
+* Virtual Function, Implementation is binder specific (IPv4 or IPv6)
+* @param Not used here
+*/
+    {
+    }
+
+void CTunDriverBinder::SetPort(TUint aPort)
+/**
+* CTunDriverBinder::SetPort is used to set port common for Ip4Binder and Ip6Binder
+* @param aPort
+* @return
+*/
+    {
+    iPort = aPort;
+    }
+
+TUint CTunDriverBinder::GetPort()
+/**
+* CTunDriverBinder::GetPort is used to obtain port common for Ip4Binder and Ip6Binder
+* @param Not used here
+* @return iPort
+*/
+    {
+    return iPort;
+    }
+
+TBool CTunDriverBinder::MatchesUpperControl(ESock::MUpperControl* /*aUpperControl*/) const
+/**
+* Virtual Function, Implementation is binder specific (IPv4 or IPv6)
+* If This MatchesUpperControl function is called, then there is an error in binding.
+* @param Not used here
+* @return EFalse.
+*/
+    {
+    return EFalse;
+    }
+
+CTunDriverBinder4* CTunDriverBinder4::NewL(CTunDriverSubConnectionFlow& aTunDriverSubConnectionFlow)
+/**
+* CTunDriverBinder4::NewL
+* This function is invoked by the flow. This CTunDriverBinder4 is IPv4 specific.
+* @param CTunDriverSubConnectionFlow
+* @return CTunDriverSubConnectionFlow.
+*/
+    {
+    CTunDriverBinder4* self = new (ELeave)CTunDriverBinder4(aTunDriverSubConnectionFlow);
+    CleanupStack::PushL(self);
+    self->ConstructL();
+    CleanupStack::Pop(self);
+    return self;
+    }
+
+void CTunDriverBinder4::ConstructL()
+/**
+* CTunDriverBinder4::ConstructL is the second-phase constructor.
+* This function is invoked by NewL.
+* This function initializes the asynchronous callback functions for sending and receiving packets.
+* @param 
+* @return.
+*/
+    {
+    TCallBack scb(SendCallBack, this);
+    iSendCallBack = new(ELeave) CAsyncCallBack(scb, EPriorityNormal);
+
+    TCallBack rcb(RecvCallBack, this);
+    iRecvCallBack = new(ELeave) CAsyncCallBack(rcb, EPriorityNormal);
+    }
+
+CTunDriverBinder4::CTunDriverBinder4(CTunDriverSubConnectionFlow& aTunDriverSubConnectionFlow) : CTunDriverBinder(aTunDriverSubConnectionFlow),iTunDriverSubConnectionFlow(aTunDriverSubConnectionFlow)
+/**
+* CTunDriverBinder4::CTunDriverBinder4 is the default constructor.
+* This function is invoked by NewL.
+* This function initializes localaddress to 0.0.0.0.
+* @param 
+* @return.
+*/
+        {
+        __FLOG_OPEN(KNif, KBinder4);
+        iLocalAddress = KInetAddrNone;
+        __FLOG_3(_L8("CTunDriverBinder4 %08x:\tCTunDriverBinder4(CTunDriverSubConnectionFlow& %08x): iLocalAddress %08x"), this, &aTunDriverSubConnectionFlow, iLocalAddress.Address());
+        }
+
+CTunDriverBinder4::~CTunDriverBinder4()
+/**
+* CTunDriverBinder4::CTunDriverBinder4 is the default destructor.
+* This function frees the RMBufPkt queues and 
+* deletes the asynchrounous call back pointers initialized at the time of construction.
+* @param 
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder4 %08x:\t~CTunDriverBinder4()"), this);
+    iRecvQ.Free();
+    iSendQ.Free();
+    delete iRecvCallBack;
+    delete iSendCallBack;
+    }
+
+MLowerDataSender* CTunDriverBinder4::Bind(MUpperDataReceiver& aUpperReceiver, MUpperControl& aUpperControl)
+/**
+* CTunDriverBinder4::Bind Binds upper CommsFramwork Protocol to this CommsFramwork Protocol.
+* @param aUpperReceiver A pointer to Upper layer Receive class
+* @param aUpperControl A pointer to Upper layer control class
+* @return this.
+*/
+    {
+    __FLOG_3(_L8("CTunDriverBinder4 %08x:\tBind(aUpperReceiver %08x, aUpperControl %08x)"), this, &aUpperReceiver, &aUpperControl);
+    iUpperReceiver = &aUpperReceiver;
+    iUpperControl = &aUpperControl;
+    return this;
+    }
+
+void CTunDriverBinder4::Unbind(MUpperDataReceiver& /*aUpperReceiver*/, MUpperControl& /*aUpperControl*/)
+/**
+* CTunDriverBinder4::UnBind UnBinds the assocication of CommsFramwork Protocol from this CommsFramwork Protocol.
+* @param aUpperReceiver A pointer to Upper layer Receive class
+* @param aUpperControl A pointer to Upper layer control class
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder4 %08x:\tUnbind()"), this);
+    iUpperReceiver = NULL;
+    iUpperControl = NULL;
+    }
+
+void CTunDriverBinder4::StartSending()
+/**
+* CTunDriverBinder4::StartSending is signaled to the upperlayer that Binder is ready to send packets.
+* This function will be called only once when the interface is started.
+* @param 
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder4 %08x:\tBinderReady()"), this);
+    iUpperControl->StartSending();
+    }
+
+TBool CTunDriverBinder4::MatchesUpperControl(ESock::MUpperControl* aUpperControl) const
+/**
+* CTunDriverBinder4::MatchesUpperControl returns whether this binder is associated with the
+* MUpperControl object passed as argument.
+* This function will be called while Unbinding the flow.
+* @param aUpperControl upper layer to match against
+* @return ETrue on a match else EFalse.
+*/
+    {
+    return (aUpperControl == iUpperControl);
+    }
+
+MLowerDataSender::TSendResult CTunDriverBinder4::Send(RMBufChain& aData)
+/**
+* CTunDriverBinder4::Send places the stack packet in SendQueue and breaks the call.
+* Then asynchrounous callback function is invoked.
+* @param aData MBuf chain containing data to send
+* @return ESendAccepted.
+*/
+    {
+    iSendQ.Append(aData);
+    iSendCallBack->CallBack();
+    return ESendAccepted;
+    }
+
+TInt CTunDriverBinder4::GetConfig(TBinderConfig& aConfig)
+/**
+* CTunDriverBinder4::GetConfig populates the interface IPv4 configuration information.
+* This function is invoked by the upperlayer
+* @param aConfig structure.
+* @return KErrNone if IPv4 binderconfiguration exists.
+* @return KErrNotSupported otherwise. 
+*/ 
+    {
+    TBinderConfig4* config = TBinderConfig::Cast<TBinderConfig4>(aConfig);
+
+    if(config == NULL)
+        {
+        return KErrNotSupported;
+        }
+    const TTunDriverIp4Provision* ip4Provision = Flow()->Ip4Provision();
+    // Setup config
+    iLocalAddress = ip4Provision->LocalAddr();
+    config->iInfo.iFeatures = KIfCanBroadcast | KIfCanMulticast;
+    config->iInfo.iMtu = KMTU;
+    config->iInfo.iRMtu = KMTU;
+    config->iInfo.iSpeedMetric = KSpeedMetric;
+    config->iFamily = KAfInet;
+
+    __FLOG_2(_L8("CTunDriverBinder4 %08x:\tGetConfig(): iLocalAddress %08x"), this, iLocalAddress.Address());
+    config->iAddress.SetAddress(iLocalAddress.Address());
+
+
+    TInetAddr address = ip4Provision->DefGateway();
+    config->iDefGate.SetAddress(address.Address());
+    // primary DNS, just make same as default gateway
+    address = ip4Provision->PrimaryDns();
+    config->iNameSer1.SetAddress(address.Address());
+    // secondary DNS
+    address = ip4Provision->SecondaryDns();
+    config->iNameSer2.SetAddress(address.Address());
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder::Control(TUint aLevel, TUint aName, TDes8& aOption)
+/**
+* CTunDriverBinder::Control is to check wether the packet is intended for tundriver or not.
+* Called from the upperlayer to identify the special control functionality.
+* Also the sets the port number.
+* @param aLevel
+* @param aName
+* @param aOption
+* @return KErrNone if packet is intended for Ipv4 tundriver.
+* @return KErrNotSupported otherwise. 
+*/ 
+    {
+    __FLOG_3(_L("CTunDriverBinder %08x:\tControl(aLevel %x, aName %x)"), this, aLevel, aName);
+    if((aLevel == KSolInetIp) && (aName == KSoTunnelPort))
+        {
+        TInetAddr& localAddress = *(TInetAddr*) aOption.Ptr();
+        SetPort(localAddress.Port());
+        return KErrNone;
+        }
+    return KErrNotSupported;
+    }
+
+TInt CTunDriverBinder4::GetName(TDes& aName)
+/**
+* CTunDriverBinder4::GetName is to retreive the Binder4 Name.
+* Called from the upperlayer. aName is filled with Binder4 Name. 
+* @param aName
+* @return KErrNone if packet is intended for Ipv4 tundriver.
+* @return KErrNotSupported otherwise. 
+*/
+    {
+    aName.Format(_L("TunDriver4[0x%08x]"), this);
+    __FLOG_2(_L("CTunDriverBinder4 %08x:\tGetName(): %S"), this, &aName);
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder4::RecvCallBack(TAny* aCProtocol)
+/**
+* CTunDriverBinder4::RecvCallBack is asynchronous callback function to send the packets to IP Layer.
+* Will be invoked whenever there is a packet in the RMBufPkt Receive Buffer.
+* @param aCProtocol contains the this object.
+* @return KErrNone 
+*/
+    {
+    ((CTunDriverBinder4*)aCProtocol)->DoProcess();
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder4::SendCallBack(TAny* aCProtocol)
+/**
+* CTunDriverBinder4::SendCallBack is asynchronous callback function to send the packets to IP Layer.
+* Will be invoked whenever there is a packet in the RMBufPkt Send Buffer.
+* DoSend will process the packets if required and place the packet in the RMBufPkt Receive Queue 
+* @param aCProtocol contains the this object.
+* @return KErrNone 
+*/
+    {
+    ((CTunDriverBinder4*)aCProtocol)->DoSend();
+    return KErrNone;
+    }
+
+void CTunDriverBinder4::DoSend()
+/**
+* CTunDriverBinder4::DoSend will retreive the packet from RMBufPkt Send Buffer.
+* Process the packets if required and puts the packet back in Receive Buffer.
+* Will be invoked by CTunDriverBinder4::SendCallback
+* @param 
+* @return  
+*/
+    {
+    RMBufPacket send;
+    RMBufPacket recv;
+    while (iSendQ.Remove(send))
+        {
+        TunnelProcessing(send,recv);
+        iRecvQ.Append(recv);
+        iRecvCallBack->CallBack();
+        send.Free();
+        }
+    }
+
+void CTunDriverBinder4::DoProcess()
+/**
+* CTunDriverBinder4::DoProcess will retreive the packet from RMBufPkt Receive Buffer.
+* send the packet to IP Layer for processing the packet.
+* Will be invoked by CTunDriverBinder4::ReceiveCallback
+* @param 
+* @return  
+*/
+    {
+    RMBufPacket packet;
+    while (iRecvQ.Remove(packet))
+        {
+        iUpperReceiver->Process(packet);
+        }
+    }
+
+void CTunDriverBinder4::TunnelProcessing(RMBufPacket& aPacket, RMBufPacket& aRecv )
+/**
+* CTunDriverBinder4::TunnelProcessing will encapsulate with IPv4 Header if the packet is to be tunneled.
+* IP Number and port number will be configure by TUN Client.
+* If the IPPacket contains TOS Option set with 192, Packet is encapsulated else packet will be send as is.
+* Will be invoked by CTunDriverBinder4::DoSend
+* @param aPacket contains the raw packet.
+* @param aRecv will contain the payload and the encapsulated IPv4 Header.
+* @return  
+*/
+    {
+    TInt  ret;
+    TUint origPktLen;
+
+    TInet6HeaderIP4* lip4 = (TInet6HeaderIP4*) aPacket.First()->Next()->Ptr();
+    TInt outerHdrLen = TInet6HeaderIP4::MinHeaderLength()
+                       + TInet6HeaderUDP::MinHeaderLength();
+    
+    if((lip4->TOS() & KTUNDriverTos) == KTUNDriverTos)
+        {
+        RMBufChain outerHdr;
+        aRecv.Assign(aPacket);
+        RMBufPktInfo *info = aRecv.Unpack();
+        aRecv.SetInfo(info);
+        
+        origPktLen = aRecv.Length();
+        TRAP(ret, outerHdr.AllocL(outerHdrLen));
+        if (ret != KErrNone)
+            {
+            RDebug::Printf("\nVirtual tunnel nif: tunnel processing: Error in Allocating the outer IP header.");
+            aRecv.Free();
+            }
+
+        aRecv.Prepend(outerHdr);
+        info->iLength += outerHdrLen;
+
+        TInet6Checksum<TInet6HeaderUDP> outerUdp(aRecv, 20);
+        if (outerUdp.iHdr == NULL)
+            {
+            RDebug::Printf("\nVirtual tunnel nif: tunnel processing: Error in Allocating the outer UDP header.");
+            aRecv.Free();
+            }
+
+        outerUdp.iHdr->SetSrcPort(GetPort());
+        outerUdp.iHdr->SetDstPort(GetPort());
+        outerUdp.iHdr->SetLength(origPktLen + TInet6HeaderUDP::MinHeaderLength());
+        outerUdp.iHdr->SetChecksum(0);       // Compute checksum
+
+        TInet6Checksum<TInet6HeaderIP4> outerIP(aRecv);
+        outerIP.iHdr->Init();
+        outerIP.iHdr->SetHeaderLength(TInet6HeaderIP4::MinHeaderLength());
+        outerIP.iHdr->SetTotalLength(origPktLen + outerHdrLen);
+        outerIP.iHdr->SetTOS(1);
+        outerIP.iHdr->SetProtocol(KProtocolInetUdp);
+        outerIP.iHdr->SetSrcAddr(iLocalAddress.Address()) ;
+        outerIP.iHdr->SetDstAddr(iLocalAddress.Address());
+        outerIP.ComputeChecksum();
+        aRecv.Pack();
+        }
+    }
+#ifdef IPV6SUPPORT
+CTunDriverBinder6* CTunDriverBinder6::NewL(CTunDriverSubConnectionFlow& aTunDriverSubConnectionFlow)
+/**
+* CTunDriverBinder6::NewL
+* This function is invoked by the flow. This CTunDriverBinder4 is IPv4 specific.
+* @param CTunDriverSubConnectionFlow
+* @return CTunDriverSubConnectionFlow.
+*/
+    {
+    CTunDriverBinder6* self = new (ELeave)CTunDriverBinder6(aTunDriverSubConnectionFlow);
+    CleanupStack::PushL(self);
+    self->ConstructL();
+    CleanupStack::Pop(self);
+    return self;
+    }
+
+void CTunDriverBinder6::ConstructL()
+/**
+* CTunDriverBinder4::ConstructL is the second-phase constructor.
+* This function is invoked by NewL.
+* This function initializes the asynchronous callback functions for sending and receiving packets.
+* @param 
+* @return.
+*/
+    {
+    TCallBack scb(SendCallBack, this);
+    iSendCallBack = new(ELeave) CAsyncCallBack(scb, EPriorityNormal);
+
+    TCallBack rcb(RecvCallBack, this);
+    iRecvCallBack = new(ELeave) CAsyncCallBack(rcb, EPriorityNormal);
+    }
+
+CTunDriverBinder6::CTunDriverBinder6(CTunDriverSubConnectionFlow& aTunDriverSubConnectionFlow) : CTunDriverBinder(aTunDriverSubConnectionFlow),iTunDriverSubConnectionFlow(aTunDriverSubConnectionFlow)
+/**
+* CTunDriverBinder4::CTunDriverBinder4 is the default constructor.
+* This function is invoked by NewL.
+* This function initializes localaddress to 0.0.0.0.
+* @param 
+* @return.
+*/        
+    {
+    __FLOG_OPEN(KNif, KBinder6);
+    iLocalAddress.SetAddress(KInet6AddrNone);
+    __FLOG_3(_L8("CTunDriverBinder6 %08x:\tCTunDriverBinder6(CTunDriverSubConnectionFlow& %08x): iLocalAddress %08x"), this, &aTunDriverSubConnectionFlow, iLocalAddress.Address());
+    }
+
+CTunDriverBinder6::~CTunDriverBinder6()
+/**
+* CTunDriverBinder4::CTunDriverBinder4 is the default destructor.
+* This function frees the RMBufPkt queues and 
+* deletes the asynchrounous call back pointers initialized at the time of construction.
+* @param 
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder6 %08x:\t~CTunDriverBinder6()"), this);
+    iRecvQ.Free();
+    iSendQ.Free();
+    delete iRecvCallBack;
+    delete iSendCallBack;
+    }
+
+MLowerDataSender* CTunDriverBinder6::Bind(MUpperDataReceiver& aUpperReceiver, MUpperControl& aUpperControl)
+/**
+* CTunDriverBinder4::Bind Binds upper CommsFramwork Protocol to this CommsFramwork Protocol.
+* @param aUpperReceiver A pointer to Upper layer Receive class
+* @param aUpperControl A pointer to Upper layer control class
+* @return this.
+*/
+    {
+    __FLOG_3(_L8("CTunDriverBinder6 %08x:\tBind(aUpperReceiver %08x, aUpperControl %08x)"), this, &aUpperReceiver, &aUpperControl);
+    iUpperReceiver = &aUpperReceiver;
+    iUpperControl = &aUpperControl;
+    return this;
+    }
+
+void CTunDriverBinder6::Unbind(MUpperDataReceiver& /*aUpperReceiver*/, MUpperControl& /*aUpperControl*/)
+/**
+* CTunDriverBinder4::UnBind UnBinds the assocication of CommsFramwork Protocol from this CommsFramwork Protocol.
+* @param aUpperReceiver A pointer to Upper layer Receive class
+* @param aUpperControl A pointer to Upper layer control class
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder6 %08x:\tUnbind()"), this);
+    iUpperReceiver = NULL;
+    iUpperControl = NULL;
+    }
+
+void CTunDriverBinder6::StartSending()
+/**
+* CTunDriverBinder4::StartSending is signaled to the upperlayer that Binder is ready to send packets.
+* This function will be called only once when the interface is started.
+* @param 
+* @return.
+*/
+    {
+    __FLOG_1(_L8("CTunDriverBinder6 %08x:\tBinderReady()"), this);
+    iUpperControl->StartSending();
+    }
+
+TBool CTunDriverBinder6::MatchesUpperControl(ESock::MUpperControl* aUpperControl) const
+/**
+* CTunDriverBinder4::MatchesUpperControl returns whether this binder is associated with the
+* MUpperControl object passed as argument.
+* This function will be called while Unbinding the flow.
+* @param aUpperControl upper layer to match against
+* @return ETrue on a match else EFalse.
+*/
+    {
+    return (aUpperControl == iUpperControl);
+    }
+
+MLowerDataSender::TSendResult CTunDriverBinder6::Send(RMBufChain& aData)
+/**
+* CTunDriverBinder4::Send places the stack packet in SendQueue and breaks the call.
+* Then asynchrounous callback function is invoked.
+* @param aData MBuf chain containing data to send
+* @return ESendAccepted.
+*/
+    {
+    iSendQ.Append(aData);
+    iSendCallBack->CallBack();
+    return ESendAccepted;
+    }
+
+TInt CTunDriverBinder6::GetConfig(TBinderConfig& aConfig)
+/**
+* CTunDriverBinder4::GetConfig populates the interface IPv4 configuration information.
+* This function is invoked by the upperlayer
+* @param aConfig structure.
+* @return KErrNone if IPv4 binderconfiguration exists.
+* @return KErrNotSupported otherwise. 
+*/
+    {
+    TBinderConfig6* config = TBinderConfig::Cast<TBinderConfig6>(aConfig);
+
+    if(config == NULL)
+        {
+        return KErrNotSupported;
+        }
+    const TTunDriverIp6Provision* ip6Provision = Flow()->Ip6Provision();
+    // Setup config
+    iLocalAddress = ip6Provision->LocalAddr();
+    config->iInfo.iFeatures = KIfCanBroadcast | KIfCanMulticast;
+    config->iInfo.iMtu = KMTU;
+    config->iInfo.iRMtu = KMTU;
+    config->iInfo.iSpeedMetric = KSpeedMetric;
+    config->iFamily = KAfInet6;
+
+    __FLOG_2(_L8("CTunDriverBinder6 %08x:\tGetConfig(): iLocalAddress %08x"), this, iLocalAddress.Address());
+
+    // primary DNS, just make same as default gateway
+    TInetAddr address = ip6Provision->PrimaryDns();
+    config->iNameSer1 = address;
+    // secondary DNS
+    address = ip6Provision->SecondaryDns();
+    config->iNameSer2 = address;
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder6::GetName(TDes& aName)
+/**
+* CTunDriverBinder4::GetName is to retreive the Binder4 Name.
+* Called from the upperlayer. aName is filled with Binder4 Name. 
+* @param aName
+* @return KErrNone if packet is intended for Ipv4 tundriver.
+* @return KErrNotSupported otherwise. 
+*/
+    {
+    aName.Format(_L("TunDriver6[0x%08x]"), this);
+    __FLOG_2(_L("CTunDriverBinder6 %08x:\tGetName(): %S"), this, &aName);
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder6::RecvCallBack(TAny* aCProtocol)
+/**
+* CTunDriverBinder4::RecvCallBack is asynchronous callback function to send the packets to IP Layer.
+* Will be invoked whenever there is a packet in the RMBufPkt Receive Buffer.
+* @param aCProtocol contains the this object.
+* @return KErrNone 
+*/
+    {
+    ((CTunDriverBinder6*)aCProtocol)->DoProcess();
+    return KErrNone;
+    }
+
+TInt CTunDriverBinder6::SendCallBack(TAny* aCProtocol)
+/**
+* CTunDriverBinder4::SendCallBack is asynchronous callback function to send the packets to IP Layer.
+* Will be invoked whenever there is a packet in the RMBufPkt Send Buffer.
+* DoSend will process the packets if required and place the packet in the RMBufPkt Receive Queue 
+* @param aCProtocol contains the this object.
+* @return KErrNone 
+*/
+    {
+    ((CTunDriverBinder6*)aCProtocol)->DoSend();
+    return KErrNone;
+    }
+
+void CTunDriverBinder6::DoSend()
+/**
+* CTunDriverBinder4::DoSend will retreive the packet from RMBufPkt Send Buffer.
+* Process the packets if required and puts the packet back in Receive Buffer.
+* Will be invoked by CTunDriverBinder4::SendCallback
+* @param 
+* @return  
+*/
+    {
+    RMBufPacket send;
+    RMBufPacket recv;
+    while (iSendQ.Remove(send))
+        {
+        TunnelProcessing(send,recv);
+        iRecvQ.Append(recv);
+        iRecvCallBack->CallBack();
+        send.Free();
+        }
+    }
+
+void CTunDriverBinder6::DoProcess()
+/**
+* CTunDriverBinder4::DoProcess will retreive the packet from RMBufPkt Receive Buffer.
+* send the packet to IP Layer for processing the packet.
+* Will be invoked by CTunDriverBinder4::ReceiveCallback
+* @param 
+* @return  
+*/
+    {
+    RMBufPacket packet;
+    while (iRecvQ.Remove(packet))
+        {
+        iUpperReceiver->Process(packet);
+        }
+    }
+
+void CTunDriverBinder6::TunnelProcessing(RMBufPacket& aPacket, RMBufPacket& aRecv )
+/**
+* CTunDriverBinder4::TunnelProcessing will encapsulate with IPv4 Header if the packet is to be tunneled.
+* IP Number and port number will be configure by TUN Client.
+* If the IPPacket contains TOS Option set with 192, Packet is encapsulated else packet will be send as is.
+* Will be invoked by CTunDriverBinder4::DoSend
+* @param aPacket contains the raw packet.
+* @param aRecv will contain the payload and the encapsulated IPv4 Header.
+* @return  
+*/
+    {
+    TInt  ret;
+    TUint origPktLen;
+
+    TInet6HeaderIP* lip6 = (TInet6HeaderIP*) aPacket.First()->Next()->Ptr();
+    TInt outerHdrLen = TInet6HeaderIP4::MinHeaderLength()
+                       + TInet6HeaderUDP::MinHeaderLength();
+    
+    if((lip6->HopLimit() & KTUNDriverTos) == KTUNDriverTos)        
+        {
+        RMBufChain outerHdr;
+        aRecv.Assign(aPacket);
+        RMBufPktInfo *info = aRecv.Unpack();
+        aRecv.SetInfo(info);
+        
+        origPktLen = aRecv.Length();
+        TRAP(ret, outerHdr.AllocL(outerHdrLen));
+        if (ret != KErrNone)
+            {
+            RDebug::Printf("\nVirtual tunnel nif: tunnel processing: Error in Allocating the outer IP header.");
+            aRecv.Free();
+            }
+
+        TInet6HeaderIP *hdrBuf = (TInet6HeaderIP*) outerHdr.First()->Buffer();
+        aRecv.Prepend(outerHdr);
+        info->iLength += outerHdrLen;
+
+        TInet6Checksum<TInet6HeaderUDP> outerUdp(aRecv, 20);
+        if (outerUdp.iHdr == NULL)
+            {
+            RDebug::Printf("\nVirtual tunnel nif: tunnel processing: Error in Allocating the outer UDP header.");
+            aRecv.Free();
+            }
+
+        outerUdp.iHdr->SetSrcPort(GetPort());
+        outerUdp.iHdr->SetDstPort(GetPort());
+        outerUdp.iHdr->SetLength(origPktLen + TInet6HeaderUDP::MinHeaderLength());
+        outerUdp.iHdr->SetChecksum(0);
+
+        TInet6Checksum<TInet6HeaderIP> outerIP(aRecv);
+        outerIP.iHdr->Init();
+        outerIP.iHdr->SetHopLimit(1);
+        outerIP.iHdr->SetNextHeader(KProtocolInetUdp);
+        outerIP.iHdr->SetSrcAddr(iLocalAddress.Ip6Address());
+        outerIP.iHdr->SetDstAddr(iLocalAddress.Ip6Address());
+        aRecv.Pack();
+        }
+    }
+    
+CTunDriverSubConnectionFlow* CTunDriverBinder6::Flow()
+    {
+    return &iTunDriverSubConnectionFlow;
+    }
+
+#endif